Vibration tests were carried out on three types of stiffened aluminum plates with fully clamped boundaries under random base excitation. During the test, the response of the specimens was monitored using strain gauges...Vibration tests were carried out on three types of stiffened aluminum plates with fully clamped boundaries under random base excitation. During the test, the response of the specimens was monitored using strain gauges. Based on the strain history, the accumulation of fatigue damage of the stiffened plates was estimated by means of the rainflow cycle counting technique and the Miner linear damage accumulation model in the time domain. Utilizing the change of natural frequencies, a nonlinear model was fitted for predicting the fatigue damage of plate and then the foregone failure criterion of 5% reduction in natural frequency is improved. The influence of section and spacing of the stiffeners on the vibration fatigue behavior of the aluminum plate was investigated. The results show that the fatigue life of aluminum plate increases with adding either T or L section riveted stiffeners. With the same cross-sectional area of stiffener, the T section stiffened plate shows longer fatigue life than L section stiffened plate. Meanwhile, the vibration fatigue life also shows great sensitivity to the spacing between the stiffeners.展开更多
Failures due to high-cycle fatigue have led to a high cost in aerospace engineering over the past few decades.In this paper,the experimental results of the fatigue behavior of compressor blade specimen subjected to re...Failures due to high-cycle fatigue have led to a high cost in aerospace engineering over the past few decades.In this paper,the experimental results of the fatigue behavior of compressor blade specimen subjected to resonance and the effects of a damping hard coating on relieving the fatigue progress are presented.The crack initiation and propagation processes were observed under resonance of the first bending mode by using the resonant frequencies as the indicator.Significant nonlinear features were observed in the spectrum of the blade with a fatigue crack.The finite element model considering the breathing crack was established with nonlinear contact based on the crack localization and size,which was obtained by ultrasonic phased array technology.The simulation results of the vibration behavior of the cracked blade were obtained and consistent with the experimental results.A NiCrAlY coating was deposited on the blade,and increases in the fatigue life were observed under the same condition.The results of this paper can help to better understand the fatigue of a compressor blade subjected to resonance and provide a preference for the application of a damping hard coating on compressor blades.展开更多
基金Project(10932008)supported by the National Natural Science Foundation of ChinaProject(B07050)supported by the Program of Introducing Talents of Discipline to Universities(111 Project),ChinaProject(2012GY2-26)supported by the Key Industry Program of Shaanxi Province,China
文摘Vibration tests were carried out on three types of stiffened aluminum plates with fully clamped boundaries under random base excitation. During the test, the response of the specimens was monitored using strain gauges. Based on the strain history, the accumulation of fatigue damage of the stiffened plates was estimated by means of the rainflow cycle counting technique and the Miner linear damage accumulation model in the time domain. Utilizing the change of natural frequencies, a nonlinear model was fitted for predicting the fatigue damage of plate and then the foregone failure criterion of 5% reduction in natural frequency is improved. The influence of section and spacing of the stiffeners on the vibration fatigue behavior of the aluminum plate was investigated. The results show that the fatigue life of aluminum plate increases with adding either T or L section riveted stiffeners. With the same cross-sectional area of stiffener, the T section stiffened plate shows longer fatigue life than L section stiffened plate. Meanwhile, the vibration fatigue life also shows great sensitivity to the spacing between the stiffeners.
基金Project(DUT20RC(3)014)supported by the Fundamental Research Funds for the Central Universities,China,Project(VCAME201801)supported by Key Laboratory of Vibration and Control of Aero-Propulsion System(Ministry of Education),ChinaProject(11472068)supported by the National Natural Science Foundation of China。
文摘Failures due to high-cycle fatigue have led to a high cost in aerospace engineering over the past few decades.In this paper,the experimental results of the fatigue behavior of compressor blade specimen subjected to resonance and the effects of a damping hard coating on relieving the fatigue progress are presented.The crack initiation and propagation processes were observed under resonance of the first bending mode by using the resonant frequencies as the indicator.Significant nonlinear features were observed in the spectrum of the blade with a fatigue crack.The finite element model considering the breathing crack was established with nonlinear contact based on the crack localization and size,which was obtained by ultrasonic phased array technology.The simulation results of the vibration behavior of the cracked blade were obtained and consistent with the experimental results.A NiCrAlY coating was deposited on the blade,and increases in the fatigue life were observed under the same condition.The results of this paper can help to better understand the fatigue of a compressor blade subjected to resonance and provide a preference for the application of a damping hard coating on compressor blades.
